Device for conveying finely divided material



Feb. 4, 1936. A. ANDREAS DEVICE FOR CONVEYING FINELY DIVIDED MATERIAL Filed Oct. 1. 1951 ma mm Te N Mr R E/Q MO M SW fl .A e g2 Patented Feb. 4, 1936 DEVICE FOR CONVEYING FINELY DIVIDED MATERIAL Arno Andreas, Munster, Germany Application October 1, 1931, Serial No. 566,275

In Germany April 5, 1930 1 Claim.

This invention relates to devices for conveying finely divided material, and more particularly to improvements in and relating to turbine constructions of the character used in machines for filling bags with such material. These turbines are commonly fed from above through an inlet conduit and deliver the material through a horizontal spout into bags whose .valve openings are located on the spout, and in known practices are subject to certain overloads of material. In other words, more material is fed to the turbine in a given period than it can discharge through the spout, the size of which is limited bycertain considerations among others the permissible size of bag valves. An undue stress is thus apt to be imposed on the turbine propeller, and there is a tendency for the material to clog the inlet conduit and the propeller housing, especially when the material is of crystalline character, such as sugar which easily becomes overheated due to friction caused by rapid handling, with the'result that particles may adhere to one another, as well as when the material is hygroscopic like cement.

The principal object -of the present invention hence resides in the provision of means for" avoiding these disadvantages, which means shall be simple and inexpensive to manufacture and eflicient in operation. Other objects and ad'-.

vantages will become apparent in connection with the following detailed description of several embodiments of my invention, reference being had to the accompanying drawing.

Referring to the drawing there is shown a propeller housing l4 including an inlet passage .l6 and an outlet passage, or spout. A propeller I5 is shown in the housing as including hub and blades for rotation with a shaft. As indicated above, if materials to be acted on by the propeller are fed into the housing vertically and across all the blades, not only is there apt to be injury caused to the propeller by the entire weight of material falling upon it, but also unnecessary swirling, by reason of the fact that a certain amount of the material is thrown back toward the inlet conduit by the propeller which is usually rotated at a high rate of speed. There is also danger of clogging especially with materials of crystalline or hygroscopic character. In order to avoid these disadvantages I have provided an inlet to the turbine which is inclined to the vertical and desirably slopes at such an angle that the material slides down the lower side of the conduit at a relatively slow and uniform rate so that all the material does not drop on the propeller at the same instant. The upper wall of the inlet I tice in bag filling machines.

conduit is shown as preferably extending upwardly sumciently and at such an angle as to cause material falling into the upper end of the conduit to strike the lower wall or material thereon before coming into contact with the propeller. 5 Moreover, by constructing the opening so that it is generally in line with the blades which are advancing the material, or in other words, so that the upper wall of the conduit is generally in line with the axis of the propeller, and conforming 10 the housing accordingly, the material is fed so that the blades which are not doing useful work are not impeded by the incoming material. Inother words, the inlet conduit is advantageously formed at an angle considerably less than vertical 15 and preferably in the order of the angle of repose of the material, and is arranged to feed the material at the working side of the propeller and mainly below the axis thereof. In some instances the slope may be even less than that 20 at which the material would ordinarily be in repose, because the suction caused by the propeller is sufficient to draw the material down the incline. The outlet conduit is shown as horizontal, or substantially so, asis the general prac- 25 The present construction, in combination with a spout of this character is also advantageous in that the blades at their lowermost positions impel the material in line with the outlet, the axis of the propeller 30 being positioned preferably at, or above, the plane of the upper wall of the outlet, while the propeller housing is rounded between the upper walls of the inlet and outlet conduits in order to provide for the rotation of the'blades as described.

In order to promote the uniformity of the stream and insure that the material does not pile up at the bottom of the conduit, it is preferable to narrow or constrict the opening at the inlet end of the conduit; for instance as shown, this constriction being particularly effective in combination with the sloping wall described. In some cases, particularly with certain types of materials, the sloping angle of the inlet conduit can- 45 not be conveniently reduced to the desired amount because, especially with the propeller stopped, the material might stall altogether while at larger angles the propeller suction causes the material to flow too rapidly, and in such cases I 50 prefer to form a bend in the inlet conduit. That is, from the hopper I! there may lead a passage l8 with a suitable sloping angle, this passage sage or conduit It, so that the speed of the'ma- 55 terial is retarded, because the material is compelled to make a right angle turn in passing from passage l8 to conduit I6. It will be understood, of course, that the narrowing is useful apart from the bend, and vice versa, and that either feature may be useful in some cases aside from the sloping conduit.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that .various modifications are possible within the scope of the invention claimed. Certain features disclosed are not claimed herein because claimed in my copending application Ser. N01 566,274, filed of even date herewith, which is now Patent No. 1,988,676, dated January 22, 1935.

I claim:

In a device for conveying finely divided materials, a turbine including a propeller and a housing therefor, an inlet conduit communicating with the housing and inclined to the vertical at such an angle that the entering material flows uniformly down the lower wall thereof, the axis of said conduit being disposed at an angle to the axis of rotation of said propeller, a hopper from which material is released into said inlet conduit, and an intermediate conduit from said hopper to said inlet conduit intersecting said inlet conduit at substantiallly a right angle, one of said conduits having a portion thereof constricted with respect to the opening of the first mentioned conduit adjacent said housing.

ARNO ANDREAS. 

